The present invention relates to a wheel suspension and more particularly a wheel suspension having a shock absorber strut and a spring element which, while the piston jamming force is reduced, only requires a relatively small installation space between the wheels of an axle and permits a low construction profile.
From the technical book "Fahrwerktechnik: Radaufhangungen" ("Chassis Technology: Wheel Suspensions") (Reimpell, J., Wurzburg, 1st Edition 1986, Page 254, FIG. 6.2/3), a wheel suspension is disclosed which has a spring strut and a one piece coil spring which is arranged diagonally with respect to the axis of the shock absorber strut, whereby an at least partial compensation of a normal wheel force is achieved, and a reduction or elimination of piston jamming forces can be achieved.
In the case of an arrangement above the wheel, the one piece coil springs result in a large overall height of the spring strut, or in the case of an arrangement next to the wheel, they result in a relatively large steering force lever arm, which has a negative effect on the directional stability characteristics of the vehicle.
A division of the spring element into two pieces and the supporting of these series connected spring elements by means of an intermediate element is disclosed by German Published, Unexamined Patent Application (DE-OS) 34 05 174. In this construction an upper spring element is arranged at the level of the section of the tire, and the intermediate element connecting the two spring elements is used for the unimpaired guiding through of a drive shaft to the wheel. In this construction, the spring elements are arranged next to the shock absorber strut so that the installation space between the wheels is reduced significantly.
Thus, it is an object of the present invention to provide a wheel suspension having a shock absorber strut and a spring element which, while the piston jamming force is reduced, requires only a relatively small installation space between the wheels of an axle and permits a low construction.
Principal advantages achieved by preferred embodiments of the invention are that, by means of a two part spring and its arrangement close to a wheel or partially in the rim nave of a wheel, an enlarged installation space is created between the wheels of an axle, and a low overall height is provided. For this purpose, the springs, operating in series, are connected with one another by an intermediate element which is arranged in the area of a ring section of the tire. In order to guide the intermediate element close to the wheel, the wheel may have a corresponding recess.
The displacing of a spring axis of the lower spring element with respect to a spring axis of the upper spring element toward the wheel causes a force which counteracts the transverse force which is always present at the body side fastening point during straight ahead driving. This force, as a function of the loading condition, may result in a neutralizing of the transverse force. This compensating effect is reinforced by the displacement of the lower suspension joint toward the outside into the wheel, because the lever arm of the vertical force affecting the wheel is shortened and thus, on the whole, smaller bearing forces are created.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.